The present invention relates to prefabricated or factory-built fireplace units intended for permanent installation, enclosed by combustible materials.
Fireplace units are commonly constructed of sheet metal, with hearth floors and sometimes rear firebox walls of refractory material, and shipped ready for installation in a building already existing or under construction. Such fireplaces are often enclosed by wood or other combustible materials and it is desirable, for maximum economy of space, that no clearance be required between the fireplace shell and the combustible materials. This requires, of course, that the outer shell of the fireplace remain cool enough to insure that an unsafe condition does not result.
Besides providing a layer of insulating material inside the fireplace shell which contacts the combustible materials, space is commonly provided for circulation of air behind the side and rear walls of the combustion chamber and beneath the hearth. In order to provide such cooling air in sufficient quantity at the required locations, air intake openings are provided below the hearth, and sometimes at other locations as well. This requires that the hearth be elevated above the level of the floor or hearth extension and that the air intake openings remain unobstructed. Besides the fact that there is a substantial possibility of inadvertently blocking these openings at or near floor level, a more esthetically acceptable appearance could be achieved by having the hearth flush with the floor or hearth extension.
It is a principal object of the present invention to provide a prefabricated fireplace construction which may be safely installed with zero clearance to combustibles which requires no inlet openings for cooling air below the front of the hearth.
Another object is to provide a factory-built fireplace unit with intake openings for cooling air which do not detract from the appearance of the fireplace and are so positioned that obstruction is unlikely.
A further object is to provide a factory-built fireplace having air intake openings for continual circulation of cooling air around the firebox with an internal structure directing the path of the air to achieve optimum cooling effect.
Other objects will in part be obvious and will in part appear hereinafter.